Two supermassive black holes on a collision course could shake the cosmos

Bursts of gravitational waves could ripple through the fabric of space-time itself.

What happens when two supermassive black holes collide?
(Photo: MLordandGod/YouTube)

A team of Caltech astronomers have discovered a pair of supermassive black holes about 3.5 billion years away from us, pirouetting inside the Virgo constellation, that are so close together that a universe-shaking collision could be imminent, reports the New York Times.

The two black holes are in a fatal gravitational dance less than 200 billion miles apart, which is practically kissing when considered on the scale of the universe. By our terms, their distance from one another is about the same as the distance between the Sun and the Oort Cloud. It's the closest that astronomers have ever come to witnessing the merger of two black holes of this size.

The theoretical effects of such a collision are difficult to fathom. It could release as much energy as 100 million supernova explosions, and send a tsunami of gravitational waves surging through the fabric of space-time itself. The cataclysmic event won't happen in our lifetimes; it is scheduled to occur in about 100,000 years. But the conditions surrounding the event should give scientists a rare opportunity to test some of our theories about the cosmos, predictions that can only be tested by extreme situations such as this.

“A scientific theory is only as good as the tests which it has passed,” said Daniel D’Orazio of Columbia University, in an email to the New York Times. Although general relativity has passed all of the observational and experimental tests thrown at it so far, some of its predictions can only be tested in the most extreme gravitational environments, namely black holes. “Detection of gravitational waves,” he said, “is a direct probe of this region and hence the secrets of gravity.”

The discovery was made after researchers caught a glimpse of a quasar known as PG 1302-102, which was flickering like an emergency beacon in a pattern that was best explained by the merging of two supermassive black holes.

Supermassive black holes can be found at the centers of almost all galaxies. If this kind of a collision were to occur in our Milky Way, then our Sun — along with all the stars in our galaxy — would be blown and scattered out into the cold abyss of space like they were hurricane debris.

Likewise, if there were ever any aliens living around any of the stars in the system highlighted by PG 1302-102, the apocalypse would certainly be nigh. It's a reminder of just how small and fragile we are in the grand scheme of the universe.